Mando Steering Research Center, Seoul National University, Seoul, Republic of Korea.
Ultrasonics. 2011 May;51(4):489-95. doi: 10.1016/j.ultras.2010.11.016. Epub 2010 Dec 4.
This study analytically investigates the propagation of shear waves (SH waves) in a coupled plate consisting of a piezoelectric layer and an elastic layer with initial stress. The piezoelectric material is polarized in z-axis direction and perfectly bonded to an elastic layer. The mechanical displacement and electrical potential function are derived for the piezoelectric coupled plates by solving the electromechanical field equations. The effects of the thickness ratio and the initial stress on the dispersion relations and the phase and group velocities are obtained for electrically open and mechanically free situations. The numerical examples are provided to illustrate graphically the variations of the phase and group velocities versus the wave number for the different layers comparatively. It is seen that the phase velocity of SH waves decreases with the increase of the magnitude of the initial compression stress, while it increases with the increase of the magnitude of the initial tensile stress. The initial stress has a great effect on the propagation of SH waves with the decrease of the thickness ratio. This research is theoretically useful for the design of surface acoustic wave (SAW) devices with high performance.
本研究分析了具有初始应力的压电层和弹性层组成的耦合板中剪切波（SH 波）的传播。压电材料沿 z 轴方向极化，并与弹性层完全结合。通过求解机电场方程，推导出了压电耦合板的机械位移和电势能函数。对于电开路和机械自由情况，获得了厚度比和初始应力对色散关系以及相速度和群速度的影响。提供了数值示例，以图形方式比较不同层的相速度和群速度随波数的变化。结果表明，SH 波的相速度随初始压缩应力的增大而减小，而随初始拉伸应力的增大而增大。初始应力对厚度比减小的 SH 波传播有很大影响。该研究对于高性能声表面波（SAW）器件的设计具有理论意义。
